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To study the synergistic lubricating effects of graphene oxide (GO) and lanthanum fluoride (LaF3), and find a new anti‐wear additive, oleic acid surface‐modified graphene oxide‐lanthanum fluoride (OA‐GO‐LaF3, OGL) composite nano‐additive was prepared by hydrothermal method by using oleic acid as the modifier. The morphology, structure, composition, element valence, thermal stability and tribological properties of nano additives were characterised by a series of modern characterisation methods. Results show that OGL has a higher degree of graphitization, smaller particle size, more homogeneous disperse, higher LaF3 load and stronger thermal stability than that of GL. The tribological properties of OGL which is modified by oleic acid are better than unmodified GL. Analysis of the friction mechanism shows that both OGL and GL can generate LaF3 physical adsorption films through adsorption during the friction process and tribochemical reactions film containing lanthanum compounds, carbon oxide compounds, and iron oxide compounds on the friction surface. These physical adsorption films and chemical reaction film can improve lubrication. [ABSTRACT FROM AUTHOR]

Due to the increasing content of carbon dioxide (CO2) in the atmosphere and the greenhouse effect issue caused by the continuous carbon emissions, the conversion of CO2 into carbon-containing clean energy has become a current research hotspot in the fields of chemistry and materials. In this study, five indium-added Zn–Al–Inx electrocatalysts were prepared via a hydrothermal synthesis method. The catalysts were characterized using analysis techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to determine their composition, structure, elemental composition and oxidation states, surface microstructure, specific surface area, and pore size. Furthermore, the electrochemical performance of these catalysts in CO2 reduction reaction (CO2RR) was investigated. Research results have revealed that the addition level of indium has a significant impact on the electrocatalytic performance of the catalysts. Among them, the Zn–Al–In0.2 hydroxide electrocatalyst with 0.2 mmol of indium addition exhibits excellent electrochemical performance in the electrocatalytic CO2RR, particularly in the production of carbon monoxide (CO). The CO faradaic efficiency (CO FE) for CO2 reduction to CO can reach up to 97.56% (−1.1 V vs. RHE), and its performance is maintained for at least 4.5 hours at −1.2 V vs. RHE. [ABSTRACT FROM AUTHOR]

The coal indirect liquefied diesel soot (Coal‐to‐liquids diesel soot, CS) was collected by a self‐made soot trapper. CS was modified with cetyltrimethyl ammonium bromide (CTAB) and named as CS‐CTAB. The tribological properties of CS and CS‐CTAB in 10#white oil(10#WO) were tested on a WTM‐2E controlled atmosphere miniature friction and wear testing machine. The morphology, composition, and tribological mechanism of CS and modified CS‐CTAB were studied by using TEM, XPS, XRD, Raman, and other instruments. The results showed that CS modified by CTAB is wrapped and entangled in long chains. Their main structure components are all amorphous carbon with a small amount of graphite crystallites. The addition of CS‐CTAB (0.8 wt%) significantly reduces both AFC and wear rate, with reductions of 32.9% for AFC, and 65.6% for wear rate compared to no additive. The anti‐friction and anti‐wear effect of CS is greatly improved after being modified by CTAB. Mechanism analysis shows that CS as a lubricant additive, acts as a micro‐bearing in the friction process and falls off under the action of shear force to generate an independent graphite sheet, thus forming a graphite protective film on the surface of 304 stainless steel plate. However, CS has the defects of low graphitization degree, large particle size, and easy agglomeration. During friction, uneven adsorption of CS on the surface can worsen wear. However, CTAB modification can improve dispersion stability in 10#WO and effectively reduce wear on the friction surface. [ABSTRACT FROM AUTHOR]

As one of the major greenhouse gases, CO2 is significantly influencing global climate change. Efficient utilization of CO2 is considered an important approach to address the current environmental and energy challenges. In particular, using CO2 as a raw material for the production of hydrocarbons is an attractive strategy for reducing carbon emissions while ensuring a stable energy supply. In this study, fluorine (F) doped ZnLa layered double hydroxide (F-ZL-LDH) and F-doped ZnCe layered double hydroxide (F-ZC-LDH) were prepared using a hydrothermal synthesis method. The materials' structural composition and morphology were analyzed using X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The research results demonstrate that both catalysts exhibit abundant active sites, high selectivity, and excellent electrocatalytic performance for CO2RR to generate CO, with Faradaic efficiencies reaching 89.29% and 89.87% for F-ZL-LDH and F-ZC-LDH, respectively. The doping of fluorine results in the presence of numerous defects and pore structures on the surfaces of F-ZC-LDH and F-ZL-LDH, increasing the surface active area and enhancing charge transfer rates. Meanwhile, F doping facilitates CO2 adsorption and mass transfer on the electrode surface. Moreover, F doping in the catalysts also restricts the adsorption and desorption of *H during the competing hydrogen evolution reaction (HER) process. The effective management and rapid conversion of CO2 to various organic compounds and chemical fuels to facilitate carbon cycle and reduce atmospheric CO2 concentration have become a hot topic in current technological advances worldwide. Among the various electrocatalytic CO2 reduction reaction (CO2RR) products, carbon monoxide (CO) is the product with the highest kinetic accessibility. In this paper, F-ZL-LDH and F-ZC-LDH composite materials were prepared using a hydrothermal synthesis method. Based on preliminary studies, a molar ratio of M2+:M3+ of 3:1 was determined to provide better catalytic performance,and ammonium fluoride content of 30% of the cation molar ratio of M2+ + M3+. The introduction of fluorine (F) improves the catalytic performance of both materials, with a greater enhancement observed for ZL-LDH. At − 1.3V vs. RHE potential, The research results demonstrate that both catalysts exhibit abundant active sites, high selectivity, and excellent electrocatalytic performance for CO2RR to generate CO, with Faradaic efficiencies reaching 89.29% and 89.87% for F-ZL-LDH and F-ZC-LDH, respectively. the fluorination treatment of ZC-LDH and ZL-LDH catalysts significantly enhances their electrocatalytic activity for the CO2 reduction reaction, particularly for the production of CO. These findings contribute to the development of efficient catalysts for CO2 electrochemical reduction and hold promise for advancing the field of CO2 utilization and renewable energy conversion. [ABSTRACT FROM AUTHOR]

Electrocatalysis serves as a highly effective approach to both mitigate greenhouse gas emissions and produce high-value chemicals. Copper-based catalysts have garnered considerable attention due to their immense potential in this domain. Improving the selectivity and activity through optimizing preparation strategies is of paramount importance. In this study, the mechanochemical method was first used for preparing copper-based composite metallic oxide electrocatalysts. Spherical CuO, Sn-CuO, and Sn-In-CuO catalysts were prepared, and their electrochemical CO2 performance was evaluated. Among them, the Sn-In-CuO catalyst demonstrated the best performance in reducing CO2 to CO products. Within the potential range of −0.6 V to −1.1 V vs. RHE, the Faradaic efficiency of the CO product was consistently above 93.56%, with a maximum Faradaic efficiency of 96.11% achieved at −0.9 V vs. RHE. Sn-In-CuO also exhibits good stability with high Faradaic efficiency of CO above 87.97% for a duration of 6 h under the potential of −0.6 V vs. RHE in a 0.1 M KHCO3 electrolyte. The excellent performance is speculated to be attributed to the generation of a large number of defects and the introduction of metal doping, which increases the number of active sites through the mechanochemical method. [ABSTRACT FROM AUTHOR]

This paper details the preparation of an aluminum-based organic metal complex doped with fluorine and nitrogen (2-Ml/Al–F–N). The synthesis method combines hydrothermal synthesis and calcination for modification. The catalyst was thoroughly characterized for its composition, structure, and morphology using various techniques, including XRD, FT-IR, XPS, SEM, TEM, and others. The electrochemical performance of the material was assessed using an electrochemical workstation, and gas chromatography was employed to analyze the results. DFT calculations were used to compute the material's properties and energy barrier diagram. The findings demonstrate that the catalyst exhibits a carbon nanoline morphology and showcases high catalytic activity in the CO2RR to CO. Notably, the catalyst exhibits excellent performance with a maximum current density of 14.08 mA cm−2 and a peak faradaic efficiency of 90.1% at −1.1 V vs. RHE. The active sites are predominantly located within the nanoline structure. The DFT calculations reveal that the introduction of ammonium fluoride during the synthesis process leads to the formation of a highly efficient fluorinated aluminum metal catalytic center derived from nonahydrate aluminum nitrate. This specific structure demonstrates excellent hydrogen suppression properties and effectively lowers desorption energy barriers, which enhances the CO2RR activity and promotes the electrocatalytic reduction of CO2 to CO. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of carbon dioxide presents a promising pathway to tackle global energy and environmental challenges. Porous carbon materials from metal‐organic frameworks exhibit high specific surface area, abundant active sites, and adjustable pore structure, demonstrating excellent electrocatalytic performance. With their abundant resources and tunability, copper‐based catalysts are well‐suited for efficient carbon dioxide conversion. However, the selectivity and stability of copper‐based catalysts is poor. This study presents the preparation of the first Cu‐doped ZIF‐8‐derived carbon materials and investigates their effect on electrocatalytic carbon dioxide reduction. At the optimal potential of −0.7 V vs. RHE, the CO Faradaic Efficiency (FE) of the Cu0.5‐N−C catalyst reaches 89 %. Furthermore, the electrochemical current density and CO FE of Cu0.5‐N−C catalyst remain nearly unchanged within 13 hours in 0.1 mol L−1 KHCO3 electrolyte. Compared to most of the reported copper‐based catalysts, Cu0.5‐N−C exhibits better stability. Characterization results show that Cu0.5‐N−C has a larger Cu‐N4, higher pyridinic N content, larger specific surface area, and average pore size, which help promote CO2 adsorption and enhance catalyst stability. This work provides new insights and pathways for electrocatalytic carbon dioxide reduction, with enormous potential to contribute to the global energy transition and environmental protection. [ABSTRACT FROM AUTHOR]

Currently, there is considerable interest in developing cost‐effective, high‐performance electrocatalysts for electrocatalytic carbon dioxide reduction (ECR). Due to their low electrical conductivity and relatively weak catalytic activity, layered bimetallic oxides have rarely been applied in ECR studies. However, they contain a large specific surface area and are rich in Lewis bases, which are favorable for CO2 adsorption. Herein, F and N co‐doped layered bimetallic oxide and reduced graphene oxide composites with precisely controlled morphology are deposited directly on carbon paper using a simple constant current electrodeposition method (FN‐NA‐CLDH@RGO‐X, X denotes the deposition time). Notably, the doping of F helps to suppress the hydrogen precipitation reaction, while the doping of N enhances the adsorption and conversion of CO2. The CO2 reduction study in an H‐type electrolytic cell shows that the FN‐NA‐CLDH@RGO‐100 s electrode‐reduced CO2 to CO at an applied potential of −1.1 V with an efficiency of 87.9% (compared to the reversible hydrogen electrode). In addition, the doping of F favors the reduction of overpotential and the improvement of catalytic activity, while the synergistic effect of F and N enhances the catalytic activity without significant decay in more than 6 h of continuous testing. [ABSTRACT FROM AUTHOR]

A self‐made soot capture device was applied to burn coal‐to‐liquids and collect its soot (CS), and then modified the CS with nitric acid or nitric acid and oleic acid to obtain nitric acid modified CS (CSN) or nitric acid and oleic acid modified CS (CSNO). The influence of CS, CSN and CSNO on the lubrication performance of 10# white oil (WO) was investigated on a four‐ball tester. The structural difference, surface topography, element composition and tribological mechanism of the three types soot were analysed by Fourier transform infrared spectrometer, X‐ray photoelectron spectroscopy, scanning electron microscope, high resolution transmission electron microscope, and so on. From the obtained results, after further modification with oleic acid, the solubility of oil is significantly improved. Compared with 10# WO, the average friction coefficient and average wear scar diameter of CS, CSN and CSNO are all reduced. Among them, CSNO has the best anti‐friction and anti‐wear effect. CSNO is expected to be used as carbon lubricating material from coal‐to‐liquids soot. [ABSTRACT FROM AUTHOR]